JP2014515611A - Integrated device for nucleic acid detection and identification - Google Patents

Abstract

  A disposable assay platform for detecting a target nucleic acid comprising a plurality of chambers and a method for operating the assay platform. The solution containing the target nucleic acid moves from one chamber to the next by opening the vent pocket. The resulting pressure change allows the solution to flow into the next chamber. The platform comprises an electronic layer and one or more fluid layers coupled together. All heating operations can be performed by using resistive heating elements in the platform. All cooling operations are preferably passive. The platform is preferably operated when oriented vertically and can be docked to an external docking station that controls the operation of the platform.

Description

(Cross-reference of related applications)
This application is incorporated herein by reference and is filed on April 20, 2011 with the title “Integrated Device for Nucleic Acid Detection and Identification”. US Provisional Application No. 61 / 477,357 and US Provisional Application No. 61/477, filed April 20, 2011, entitled “Oscillating Amplification Reaction for Nucleic Acids”. Claim priority and interest of 437 application.
References to sequence descriptions, tables or computer programs

Applicant made the 042012_ST25.04 April 20, 2012, which is ASCII compliant and has 2 kilobytes and is incorporated herein by reference. The sequence description is submitted here as a text file named txt.

  Embodiments of the invention relate to integrated devices and associated methods for detecting and identifying nucleic acids. The device may be fully disposable or may comprise a disposable part and a reusable part.

  Note that the following discussion refers to several publications and references. The discussion of such publications is provided herein for a more complete background of scientific principles and acknowledges that such publications are prior art for purposes of determining patentability. Should not be interpreted as.

  As the impact and awareness of infectious and manifestation diseases, biological threat factors, genetic diseases and environmental reservoirs of environmental pathogens increase in public health and awareness, they are more informative and more sensitive The demand for specific point-of-use rapid assays has increased the demand for polymerase chain reaction (PCR) based tools. Nucleic acid-based molecular testing by methods such as PCR-based amplification is extremely sensitive, specific, and informative. Unfortunately, the currently available nucleic acid tests are unsuitable for use in the field or have limited utility because they are complex and expensive instruments, specialized experiments This is because multiple operations depending on the material and / or user intervention are required. As a result, most samples for molecular testing are sent to a centralized laboratory, which takes a long time to obtain the necessary information.

  To address the need for rapid point-of-use molecular testing, efforts have been focused on product design using disposable cartridges and relatively expensive associated equipment. The use of external equipment to achieve fluid transfer, amplification temperature control and detection simplifies many of the technical challenges inherent in integrating the multiple steps required for molecular testing. Unfortunately, relying on complex equipment presents significant economic barriers for small clinics, local and state governments, and law enforcement agencies. In addition, reliance on a small number of equipment to perform testing can cause unnecessary delays in demanding periods, such as those that are suspected of being released by biological weapons or emerging epidemics. . In fact, instrument and disposable reagent cartridge models can cause potentially significant bottlenecks when large volumes require increased throughput and increased throughput. In addition, the dependence on equipment complicates the occasional installation of test equipment at the location, where bulky related equipment is excluded due to logistics constraints or infrastructure requirements (eg, reliable) Does not exist.

  Gravity has been described as a fluid moving means in existing microfluidic devices. However, conventional devices do not allow such programmed or electronic control of fluid movement or mixing of more than two fluids. Some devices also take advantage of the pressure drop generated by dropping an inert or prepackaged fluid to create a slight vacuum, allowing reactants to enter the process chamber when oriented vertically. Although aspirating, this increases the complexity of storage and transportation to ensure the stability of the packaged fluid. Existing devices that teach moving fluids in multiple discrete steps require a fragile seal or valve between the chambers, which complicates operation and manufacturing. These devices do not teach a separate remotely located vent for each chamber.

  Typical microfluidic devices typically utilize a smaller reaction volume than is used in standard laboratory procedures. PCR or other nucleic acid amplification reactions such as loop-mediated amplification (LAMP), nucleic acid-based sequence amplification (NASBA) and other isothermal and thermal cycling methods are typically tested and studied using reaction volumes of 5 to 100 microliters Done in the room. These reaction volumes contain sufficient test sample volume to reliably detect small assay targets in the diluted sample. Compared to those used in conventional laboratory molecular testing, microfluidic systems that reduce the reaction volume inevitably reduce the volume of sample that can be added to the reaction. As a result of the smaller reaction volume, the ability to accommodate sufficient sample volume to allow for the presence of detectable amounts of target in diluted samples or where assay targets are insignificant.

  One embodiment of the present invention is a disposable platform for detecting a target nucleic acid, a sample chamber for containing a sample containing the target nucleic acid, coupled to the sample chamber via a first channel, and a second channel An amplification chamber connected to the first vent pocket via the third channel, a labeling chamber connected to the amplification chamber via the third channel and connected to the second vent pocket via the fourth channel, and a fifth channel A detection subsystem connected to the labeling chamber via a sixth channel and connected to a third vent pocket via a sixth channel, a plurality of resistive heating elements, and one or more temperature measurement devices, wherein the vent pocket is Each of the resistance heating elements is sealed from the atmosphere by a non-heat resistant membrane located near one of the resistance heating elements. It is a platform Te. The disposable platform optionally further comprises a sample preparation stage with an outlet in direct fluid communication with the inlet of the sample chamber. The substantially planar dimension of the amplification chamber is preferably approximately the same as the substantially planar dimension of the resistive heating element in thermal contact with the amplification chamber. The amplification chamber is preferably not cooled by an active cooling device. The amplification chamber optionally contains an amplification solution, the sample chamber optionally contains a liquid amplification reagent mix or a lyophilized amplification reagent mix, and / or the label chamber optionally contains detection particles. The labeling chamber is preferably heatable using one of the resistive heating elements. The detection subsystem preferably includes a lateral flow strip that does not include detection particles. The chamber, channel and vent pocket are preferably located on the fluid assembly layer and the electronic element is preferably located on a separate layer including the printed circuit board, the separate layer being coupled to the fluid assembly layer. . The detection subsystem is preferably located on the fluid assembly layer or optionally on the second fluid assembly layer. The volume of the at least one chamber is preferably between about 1 microliter and about 50 microliters. The disposable platform preferably further comprises a connector for coupling the disposable platform with a base unit that holds the disposable platform in a vertical or tilted orientation rather than an external device.

  One embodiment of the present invention is a method of detecting a target nucleic acid comprising placing a sample containing the target nucleic acid in a sample chamber of a disposable platform and directing the disposable platform vertically or tilted. And reacting the sample with liquid or previously lyophilized amplification reagent mix and opening the first vent pocket connected to the amplification chamber to the atmosphere so that the reacted sample can flow into the amplification chamber. And amplifying the target nucleic acid in the amplification chamber, and opening the second vent pocket connected to the labeling chamber to the atmosphere so that the amplified target nucleic acid can flow into the labeling chamber. Labeling the amplified target nucleic acid using the detection particles in the labeling chamber; By the third vent pocket is connected to the stem to open to the atmosphere, it consists of the labeled target nucleic acid to be able to flow into the detection subsystem, and detecting the amplified target nucleic acid. The amplification step preferably includes amplifying the target nucleic acid using a resistive heating element located in the disposable platform near the amplification chamber. The method preferably further includes passively cooling the amplification chamber. The method preferably further includes heating the labeling chamber using a resistive heating element located near the labeling chamber in the disposable platform during the labeling step. The detection subsystem is preferably free of detection particles. The method preferably further includes controlling the operation of the disposable platform by using a docking station that is not an external device.

  The objectives, advantages and novel features of the invention, as well as further scope of application, are set forth in part in the following detailed description, in conjunction with the accompanying drawings, and in part will be apparent to those skilled in the art upon consideration of the following. It will become apparent or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

  The accompanying drawings, which are incorporated in and form a part of the specification, illustrate several embodiments of the invention and, together with the description, serve to clarify the principles of the invention. The drawings are only for purposes of illustrating certain embodiments of the invention and are not to be construed as limiting the invention. In the drawing

FIG. 3 shows a fluid layer and an electronic layer for one embodiment of the present invention. The prepared sample fluid enters the sample chamber where it is preferably mixed with the lyophilized reagent. In the vertical orientation, the pressure of the fluid column is in equilibrium with the volume of sealed air below it. Capillary action prevents air escape and further fluid progression. When the appropriate vent seal under the corresponding vent pocket breaks, fluid moves through the outlet channel to the next chamber for further processing. Temperature and fluid control is preferably achieved using standard printed circuit assembly (PCA) components and assembly techniques. FIG. 2 is a schematic diagram of a vent mechanism used in one embodiment of the present invention to control fluid movement within a fluid layer. It is a figure which shows the position and structure of a vent in one Embodiment of this invention. The membrane maintains the fluid column pressure above ambient pressure. When enough heat is applied, the membrane breaks and balances the pressure. The fluid moves along a hydrostatic pressure gradient. The pressure can be less than a few mbar. Fig. 4 shows details of a further resistance heater of an embodiment of the invention. Two 2512 size thick film surface mount device (SMD) resistors (heating elements) are in contact with the 0402 size thermistor (temperature sensor) on the side on the printed circuit board (PCB). Thermal conductivity to the heater and sensor is maintained by a thin layer of thermal compound at the resistor / amplifier chamber interface. The chamber dimensions are preferably selected to maximize the area / volume ratio. 3 illustrates an embodiment of the invention corresponding to either thermal cycling or isothermal based nucleic acid amplification methods. A PCA with four resistor / thermistor pairs is shown. The four surface mount resistors act as four independently controllable heaters (arrows). 4B shows a fluid assembly coupled to the PCA of FIG. 4A, consistent with the details of the resistance heater of FIG. The fluid layer interfaces with PCA surface mount resistors to provide a reaction chamber for nucleic acid amplification. FIG. 6 shows gel electrophoresis of an amplification reaction that produces an approximately 150 bp (base pair) product from a PCR device (LAB) or by one embodiment of the present invention (μ heater) by thermal cycling. The leftmost lane is the size standard. It is a graph of temperature vs. time (second) about the fluid in the amplification chamber of this embodiment. The dark line indicates the temperature of the solution in the reaction chamber obtained by the thermocouple. The bright line is the temperature measured by the thermistor used by the microcontroller for temperature control. 40 cycles of a two temperature PCR reaction can be achieved in less than 20 minutes using a 20 μL reaction volume. Shows gel electrophoresis of an isothermal nucleic acid sequence-based amplification (NASBA) reaction that produces an approximately 150 bp product from a PCR device (positive control) or by using one embodiment of the present invention. The four separate reactions show both the temperature sensor setting and the specific surface treatment applied inside the fluid chamber. 1 illustrates one embodiment of the present invention including a technique for conveying fluid without using a vent. By heating the chamber under the fluid column, the gas expands and the gas itself is removed through the inlet channel. Upon cooling, the gas in the chamber volume contracts, drawing a volume of fluid proportional to the volume of gas removed. The fluid falls to the bottom of the chamber. This cycle can be repeated continuously to move the entire reaction volume. The operation of this technique depends on channel size, length, heating time and temperature, chamber volume and component surface energy. 2 shows details and functions of a labeling chamber of one embodiment of the present invention. A fluid containing the amplicon enters the labeling chamber through the inlet channel and contacts the detection particles. Sufficient mixing is achieved by heating or boiling the fluid. Preferably texture features of the chamber, such as a laser etched line or series of lines, raise the nucleated bubbles at the bottom and sides, preferably effectively stirring the mixture. In this embodiment, the SMD components are the same as those used in the amplification heater. It is a component of the fluid layer of one Embodiment of this invention. A wall component of a selected thickness is joined to the two sides by a surface component. In one embodiment, the wall component is 0.5 mm laser cut acrylic and the surface is a 0.004 inch polyester (PET) film. The parts are preferably bonded together by a silicone transfer adhesive. The internal surface is treated to control wetting. Reagents and lateral flow assemblies are added during manufacturing. The adhesive membrane is preferably sealed over the vent pocket. Fig. 6 shows the PCA side facing the fluid assembly of one embodiment of the present invention, wherein the heating element is a thick film resistor. The temperature sensor is a small SMD thermistor positioned very close to the heater. The PCA may optionally include an indicator LED for monitoring assay progress, heating and vent opening. FIG. 5 shows a fluid cassette joined to PCA by an adhesive shim according to one embodiment of the present invention. Shim thickness can be important for proper spacing and function of the vent and heater. 1 shows a semi-disposable disposable PCA according to an embodiment of the present invention. The PCA contains only electronic components that interface with the disposable fluid assembly. This includes a heating element, a temperature sensor and optionally an LED indicator. There are connectors for completing the circuit and possibly adding support vertically. FIG. 10B shows the disposable PCA / fluid assembly of FIG. 10A located at the docking station. The docking station contains control electronics and a power source, and in some cases is easy to move and carry. A disposable part containing the PCA and fluid assembly is inserted into the connector, preferably vertically. A user interface including a display LED, LCD and user control device may optionally be present in some embodiments. The docking station may include a button that initiates the electronic steps required for the assay. 1 is a front view of a PCA according to an embodiment of a disposable inventive configuration of the present invention. This side faces the fluid assembly. Heating and sensor elements and user interface components such as LED indicators are present in this embodiment. It is a figure which shows the layout of the back surface of PCA of the structure of the disposable present invention of FIG. 11A. This side of the PCB holds the control circuitry, such as a microcontroller, MOSFET switch, and auxiliary circuitry. In this embodiment, there are terminals for 9V batteries as well as any user interface device, such as a tactile switch useful for starting an assay. FIG. 11B is a diagram of the PCA of FIG. 11B with a 9V battery installed. The plastic housing is not shown. A battery arrangement is preferred, as shown, to reduce the center of mass and to help prevent tilting or rollover of the device during operation. FIG. 4 is a diagram of a semi-disposable embodiment of the present invention in which a sample preparation subsystem is interfaced with amplification and detection fluidic elements and electronic components. FIG. 4 illustrates components of one embodiment of a multilayer fluid layer that is incorporated into a disposable assay. FIG. 14 shows an exploded view of a disposable assay cartridge incorporating the fluid layer of FIG. 13. FIG. 15 illustrates the assembled disposable PCA / fluid assembly of FIG. 14 positioned at a docking station. 2 shows a photograph of a fluid layer of one embodiment of the invention in support of thermocycle-based nucleic acid amplification and detection. A reaction solution containing all the reagents necessary to support nucleic acid amplification was added to the sample chamber. The required enzyme was added to the reaction solution in liquid form. The required enzyme was supplied by the incorporation of lyophilized pellets into the sample chamber. Nucleic acid amplification and detection was performed as described in Example 1. The top line of the detection strip assembly represents an oligonucleotide complementary to the detection probe, which is a positive control. The line immediately below the positive control represents the immobilized oligonucleotide complementary to the same amplification product strand as the detection probe, which is the capture line. FIG. 4 is a photograph of a sample-to-result nucleic acid test device manufactured by interfacing with a sample preparation subsystem according to the present invention. Embodiments of the present invention support a single integrated device for nucleic acid isolation, amplification and detection. Nucleic acid isolation, amplification and detection were performed as described in Example 2. The top line of the lateral flow assembly represents the oligonucleotide complementary to the detection probe, which is a positive control. The line immediately below the positive control represents the immobilized oligonucleotide complementary to the same amplification product strand as the detection probe, which is the capture line. After completion of the processing of macerated soft tissue from citrus trees suffering from citrus greening disease and the assay of nucleic acids isolated by an integrated sample preparation system, Candidatus Riberiberta, the virulence factor of citrus greening Is shown about. FIG. 4 is a photograph of a sample-to-result nucleic acid test device manufactured by interfacing with a sample preparation subsystem according to the present invention. Embodiments of the present invention support a single integrated device for nucleic acid isolation, amplification and detection. Nucleic acid isolation, amplification and detection were performed as described in Example 2. The top line of the lateral flow assembly represents the oligonucleotide complementary to the detection probe, which is a positive control. The line immediately below the positive control represents the immobilized oligonucleotide complementary to the same amplification product strand as the detection probe, which is the capture line. After completion of the processing of macerated soft tissue from citrus trees suffering from citrus greening disease and the assay of nucleic acids isolated by an integrated sample preparation system, Candidatus Riberiberta, the virulence factor of citrus greening Is shown about.

  Embodiments of the present invention integrate instrumental independent means to perform all the necessary steps of a nucleic acid molecule assay, providing a current immuno-lateral flow rapid assay, more informative and sensitive analysis Includes a disposable platform that is complemented by a new generation of nucleic acid tests. Embodiments of the present invention provide broader use of rapid nucleic acid tests in small clinics and austering settings where infectious diseases, biological threat pathogens, agricultural and environmental tests are most likely to have an impact To make it easier. Certain embodiments of the present invention are completely stand-alone and disposable, so they can “increase processing power” when demand increases by performing parallel testing without the bottleneck being imposed by equipment. It becomes. In addition, in applications where a low cost disposable cartridge coupled with an inexpensive battery-powered or AC adapter powered docking station is preferred, it can be reused by one embodiment of the present invention where a simple docking station is used. By placing reusable components on an inexpensive base, test costs are further reduced. The platform technology disclosed herein is as sensitive as laboratory nucleic acid amplification-based methods, minimal user intervention and training requirements, sequence specificity provided by both amplification and detection, multiplex throughput, stability New reagents, compatibility with low-cost large-scale manufacturing, battery operation for use in austere settings, and the incorporation of additional or alternative biomarkers that do not require device redesign Provide flexible platform technology.

  Embodiments of the present invention provide for low-cost point-of-use nucleic acid detection and identification suitable for performing analysis away from the laboratory environment in which testing is typically performed. Systems and methods are provided. Advantageously, the nucleic acid amplification reaction volume can be in the same volume range (eg 5-100 μL) as commonly used in conventional laboratory tests. The reactions performed in the embodiments of the present invention can thus be directly compared to commonly accepted laboratory assays and can accommodate the same sample volumes commonly used in conventional molecular tests.

  Embodiments of the invention may be used to detect the presence of one or more target nucleic acids in a sample. The target sequence may be DNA, such as chromosomal DNA or extrachromosomal DNA (such as mitochondrial DNA, chloroplast DNA, plasmid DNA, etc.) or RNA (such as rRNA, mRNA, small RNA and viral RNA). Similarly, embodiments of the invention may be used to identify nucleic acid polymorphisms including single nucleotide polymorphisms, deletions, insertions, translocations and sequence duplications. Furthermore, embodiments of the invention may be used to detect gene regulatory events, such as gene upregulation and downregulation at the transcriptional level. Thus, embodiments of the present invention include 1) detection and identification of pathogen nucleic acids in agricultural, clinical, food, environmental and veterinary samples, 2) detection of genetic biomarkers of disease, and 3) of disease or metabolic status Gene-regulatory events (during mRNA up- or down-regulation or disease or metabolic status in response to the presence of disease or metabolic status, eg pathogens, toxins, other virulence factors, environmental stimuli or metabolic status through detection of relevant biomarkers It may be used for applications such as the diagnosis of small RNA or other nucleic acid molecules produced or suppressed).

  Embodiments of the present invention include means for preparing, amplifying and detecting a target nucleic acid sample upon addition of the nucleic acid sample, including all aspects of fluid control, temperature control and reagent mixing.

  In some embodiments of the invention, the device provides a means for performing nucleic acid tests using a mobile power source, such as a battery, and is completely disposable. In other embodiments of the invention, disposable nucleic acid test cartridges operate in conjunction with simple reusable electronic components that do not perform all the functions of typical laboratory equipment.

  Embodiments of the present invention provide, but are not limited to, nucleic acid amplification and detection devices comprising a housing, a circuit board, and a fluid or microfluidic layer. In certain embodiments, the circuit board may contain a wide variety of surface mount components, such as resistors, thermistors, light emitting diodes (LEDs), photodiodes and microcontrollers. The fluid or microfluidic layer is responsible for the movement of the aqueous reaction volume and includes a wide variety of plastics, including joining, fusing or laminating pieces of laser cut, water jet cut or injection molded pieces. It may be made by manufacturing techniques. The fluidic elements and circuit board components may be combined and their thermal coupling may be improved by a thermally conductive material or compound. The housing preferably acts as a surface protective sheath, partially covering the delicate components of the microfluidic and circuit board layers, and initiates the steps necessary for sample input, buffer release, nucleic acid elution and device function. It may also play a role in facilitating. For example, the housing may include a sample input port, user action, buffer release, sample flow initiation and / or buttons or similar mechanical features that allow nucleic acid elution.

  In some embodiments of the invention, the fluid or microfluidic layer preferably comprises four chambers including a sample input chamber, an amplification chamber, a nucleic acid labeling chamber and a detection chamber. The solution input chamber preferably comprises a sample input orifice into which a nucleic acid containing sample can be added, and an exit line that reaches the amplification chamber. The sample input chamber may contain suitable buffers, salts, deoxyribonucleotides, ribonucleotides, oligonucleotide primers, and lyophilized reagents including enzymes such as DNA polymerase and reverse transcriptase. Such lyophilized reagents are preferably solubilized upon addition of the nucleic acid sample. The amplification chamber is preferably positioned in alignment with the heater element on the circuit board and is in thermal contact with the heater element. Similarly, electronic components present on the circuit board are placed in physical contact with or near the vent or valve structure of the fluid layer to allow electronic control. Since the physical layout of the circuit board is designed to align with the elements of the fluid or microfluidic layer, the resistive heating elements of the circuit board for amplification and / or fluid flow control interact with these elements Positioned to form a contact with the fluid component element.

  Other embodiments of the invention include nucleic acid amplification and detection devices integrated with sample preparation devices. Embodiments that include a sample preparation device provide fluid communication means between the sample preparation subsystem outlet port or valve and one or more input ports of the fluid or microfluidic component of the device.

  Unless defined otherwise, all technical terms, notations, and other scientific terms used herein are intended to have the meanings commonly understood by one of ordinary skill in the art to which this invention belongs. The techniques and procedures described or referenced herein are generally well understood by those of ordinary skill in the art and are conventional methods such as the Cold Spring Harbor Laboratory magazine, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY. Laboratory Press, Sambrook et al., “Molecular Cloning: A Laboratory Manual”, 3rd edition (2001), and John Wiley and Sons, Inc. (John Wiley & Sons, Inc.) edited by Ausbel et al., “Current Protocols in Molecular Biology” (2001). Are commonly used. Where appropriate, procedures involving the use of commercially available kits and reagents are performed according to manufacturer defined protocols and / or parameters unless otherwise stated.

  As used throughout the specification and claims, the term “target nucleic acid” or “template nucleic acid” means a single- or double-stranded DNA or RNA fragment or sequence that is intended to be detected. .

  As used throughout the specification and claims, the term “microparticle” or “detection particle” refers to fluorescent dyes, fluorescent modified oligonucleotides and oligonucleotide conjugate quantum dots or solids specific for double-stranded nucleic acids. Any compound used to label a nucleic acid product produced during an amplification reaction, including phase elements such as polystyrene, latex or paramagnetic particles or microspheres.

  As used throughout the specification and claims, the term “chamber” means a fluid compartment in which a fluid stays for a period of time before going to another chamber. For example, the chamber may be a sample chamber, an amplification chamber, a label chamber or a detection chamber.

  As used throughout the specification and claims, the term “pocket” means a compartment overlying a resistor or other mechanism that acts as a venting mechanism. For example, unlike the fluid chamber described above, a pocket made in the fluid layer may have one open surface that is aligned with a resistor on the PCA. This open surface is preferably covered with a thin membrane, creating a sealed void that is easily broken by energizing the underlying resistor.

  As used throughout the specification and claims, the term “channel” refers to a fluid assembly that typically connects two or more chambers and / or pockets or combinations thereof, including, for example, an inlet, outlet or vent channel. It means a narrow pipe line. In the case of an inlet or outlet channel, the fluid sample moves through the channel. In the case of a vent channel, the conduit remains fluid free and connects the fluid chamber to the vent pocket.

  As used throughout the specification and claims, the term “external instrument” refers to heating and / or cooling a disposable assay and / or to a disposable assay, including but not limited to a buffer. It refers to a reusable device that performs mechanical actions, including piercing an agent pack and / or pumping fluid or otherwise actively providing transport force to the fluid.

  Embodiments of the present invention are devices for low-cost point-of-use nucleic acid testing that are suitable for performing analysis away from the laboratory environment in which testing is normally performed. is there. Some devices comprise fluid and electronic components or layers, optionally contained in a protective housing. In an embodiment of the invention, the fluid layer is a series of chambers and pockets composed of plastic and connected by thin channels, in which the chambers are oriented perpendicular to each other during operation. The fluid layer is overlaid on a printed circuit board containing electronic components such as off-the-shelf surface mount devices (SMD) or otherwise placed in physical contact with the printed circuit board Be controlled. In some embodiments of the device, the entire assembly is disposable. In other embodiments, the fluid layer and the physically coupled electronic layer are disposable, but a small, inexpensive control unit is reusable. In another embodiment, the fluid layer is disposable and the small control base unit is reusable. For all embodiments, the present invention refers to “Highly Simplified Lateral Flow-Based Nucleic Acid Sample Preparation International Publication 9” entitled “Highly Simplified Lateral Flow-Preparation and Passive Fluid Flow International 9”. / 137059 (A1) pamphlet (incorporated herein by reference) and may be combined with nucleic acid sample preparation devices and / or methods of use described therein.

  Embodiments of the present invention include integrated nucleic acid test devices that can be manufactured inexpensively by established manufacturing processes. The present invention adjusts the fluid temperature within the device while maintaining simplicity from the end-user's point of view of a widely accepted portable immunoassay, transporting small sample volumes in successive steps, Mixing reagents, overcoming the challenges of detecting nucleic acids and providing molecular test data. Embodiments of the present invention are uniquely suited for the use of off-the-shelf electronic elements that can be constructed by standard assembly techniques and do not require moving parts. In addition, the fluid layer design allows readily available plastics and manufacturing techniques to be used. The result is an inexpensive, disposable and reliable device that can isolate, amplify and detect nucleic acids without the need for dedicated laboratory facilities.

  Existing nucleic acid test devices generally use high performance heating elements such as deposited film heaters and Peltier devices, which are significantly costly and / or require special manufacturing methods. In embodiments of the present invention, heating of the reaction solution is accomplished by using a simple resistive surface mount device, which can be purchased, preferably in a few penny or less, and is assembled and tested according to common manufacturing standards. The fluid temperature of the reaction solution may be conveniently adjusted by overlaying the fluid chamber over these resistive elements and associated sensor elements. The widespread use of SMD resistors in the electronics industry ensures that the present invention follows established quality control methods. Many nucleic acid amplification techniques, such as PCR, require not only rapid heating of the reaction solution, but rapid cooling as well. The reaction chamber of the present invention preferably heats on one side and uses ambient temperature on the opposite side to help lower the fluid temperature. In addition, the vertical orientation of the device embodiments allows passive cooling to allow faster cooling than if the device were oriented horizontally, thus eliminating the need for expensive fans or Peltier devices. The cycle period is shortened.

  Fluid control is another challenge associated with low cost nucleic acid test device design. Devices known in the art typically use an electromechanical, electrokinetic or piezoelectric pumping mechanism to manipulate fluid during device operation. These pumping elements increase both device complexity and cost. Similarly, elaborate micromechanical designs or valves utilizing moving parts can increase manufacturing costs and reduce reliability due to complications such as moving parts failure or biofouling. Unlike the previously described nucleic acid test devices, embodiments of the present invention utilize microcontroller-controlled hydrostatic pressure along with capillary forces and surface tension to manipulate fluid volume. The vertical orientation of some embodiments of the present invention allows reaction solutions to be transferred from chamber to chamber under microcontroller control to accommodate the operations required for the assay. Fluid can be held in individual reaction chambers by a balance of channel size and surface tension, where the surface tension hinders fluid progression by the elimination of gas. The sample proceeds to the lower chamber immediately after activation of the simple venting mechanism, preferably under microcontroller control. Once opened, the vent moves fluid from the first chamber to the second chamber by providing a path for the displaced air to exit the second chamber upon entry of the fluid. Each chamber in the fluid layer is preferably connected to a sealed vent pocket through a narrow vent channel. The vent pocket is preferably sealed on one side by a thin plastic membrane and the membrane is easily broken by heating a small surface mount resistor under the membrane. Once the lower chamber vent is open, fluid progression occurs even under low hydrostatic pressure.

  As will be described in more detail below, the fluid or microfluidic valve mechanism in some embodiments of the present invention preferably comprises a heating element in thermal and (although not essential) physical contact with a non-heat resistant seal. It is used to allow electronic control of fluid movement by venting a lower altitude chamber and allowing fluid from the higher altitude chamber to flow into the lower chamber. In one embodiment, the surface mount resistor is in physical contact with a channel seal that is mounted on a printed circuit board and constructed of a non-heat resistant material using widely used and established electronic component manufacturing methods. Are arranged. A surface mount resistor generates enough heat to energize the seal when energized, thereby venting the chamber and lowering the pressure, for example ambient pressure, and thus lowering the altitude from a higher altitude chamber Fluid is moved into the chamber. A direct seal between a higher altitude chamber and a lower altitude chamber is preferably not used. Channels and seals may be placed away from the fluid chamber, which facilitates fluid device layout in an efficient arrangement for manufacturing. The sealing material can include any thin plastic sheet, for example, which seals the vent channel and can be thermally broken as described. Such an approach to fluid movement control in a device benefits from low material costs, suitability for manufacturing using established stacking and electronic component manufacturing techniques, and the use of electronic control circuits such as microprocessors or microcontrollers. Provides the ability to move fluid through a series of chambers under control. By using vents, non-heat-resistant materials that seal the vents (and fluid chambers or fluid microchannels themselves) and electronic means that break the seals with heat, at a given time or for certain events (eg, temperature Providing a means for controlling fluid flow through the device to allow movement of the fluid after completion of a temperature change, temperature change or series of temperature changes or completion of one or more incubation times or other events.

  In addition, the vent approach has several advantages over sealing the fluid chamber itself. The vent pocket can be located anywhere in the fluidic element layout and can easily communicate with the chamber that the vent pocket adjusts through the vent channel. From a manufacturing point of view, the vent pocket can be localized so that only one sealed membrane for all vent pockets (which may be provided with a vent pocket manifold), preferably adhesive, thermal lamination, It is applied to the fluid layer by established methods such as ultrasonic welding and laser welding. In contrast, in a direct sealed fluid chamber, the seal material is more difficult to manufacture because it needs to be placed at different locations corresponding to the location of each chamber. This presents a more challenging scenario during manufacture compared to a single vent pocket manifold sealed by a single membrane.

  In addition, the sealing material located in the chamber tends to come into contact with the solution held in the chamber. This requires the use of materials that (i) do not interfere with the reaction taking place in the chamber and (ii) are not affected by the solution. Given the sensitivity of biochemical reactions to high temperatures used for both chemical inhibitors and amplification and labeling prior to detection, the list of acceptable materials becomes limited. In addition, the close proximity of the heat sensitive material directly associated with the reaction chamber used to carry out the reaction at high temperatures, in addition to preventing the solution from heating when the sealing material melts, during the reaction A significant challenge is presented to ensure thermal insulation of the valve seal material from the high temperatures used in In order to avoid valve breakage, the heat sensitive material needs to be located away from the heat source or the heat sensitive material needs to be activated at a temperature much higher than the highest temperature used in the reaction. Remotely placed seals, directly associated with the miniaturized device chamber, impose constraints on the fluid element layout and prevent the use of small physical designs. And the use of higher temperatures to actuate valves located at the reaction chamber sites can be detrimental to biochemical components that lose stability at slightly higher temperatures than the reaction temperatures used. Finally, if the chambers are sealed directly, melt seal material may remain in the channels between the chambers and block the flow. Depending on the viscosity of the sealing material, a higher pressure may be required in the liquid column than can be obtained with a miniaturized gravity drive.

  In embodiments of the present invention, reagent mixing does not require complexity over other systems. Reagents necessary for nucleic acid amplification, such as buffers, salts, deoxyribonucleotides, oligonucleotide primers and enzymes, are preferably stably incorporated by using lyophilized pellets or cakes. These lyophilized reagents sealed in a fluid chamber can be immediately solubilized upon contact with an aqueous solution. If additional mixing is required, the vertical orientation of embodiments of the present invention provides an opportunity for a new method of mixing solutions. When the solution contains a thermosensitive component, the gas can be heated by using a heater below the fluid chamber, and bubbles are delivered to the reaction solution in the upper chamber. Alternatively, if the solution does not contain a heat sensitive component, a heater may be used to heat the solution directly to the temperature at which boiling occurs. Bubble generation is often undesirable in previously disclosed fluid and microfluidic devices because bubbles can accumulate in fluid chambers and channels to eliminate reaction solutions or prevent fluid movement within the device. Because there is. Due to the vertical design of the embodiments of the invention presented herein, the bubbles are raised to the fluid surface, resulting in minimal and temporary fluid exclusion, and the adverse effects of the bubbles on the fluid or microfluidic system. Both improve effectively. Mixing by boiling is also convenient with this vertical design, because the fluid that was rejected during the process is easily returned to the original fluid chamber by gravity after the heating element is shut off.

  In an embodiment of the invention, a colorimetric detection strip is used to detect amplified nucleic acid. Lateral flow assays are commonly used in immunoassay tests because of their ease of use, high reliability and low cost. The prior art also consists of a porous material for nucleic acid detection using a porous material as a sample receiving area at or near a labeling area located at or near one end of a lateral flow assay device. Contains a description of the use of lateral flow strips. In these prior inventions, the label moiety is in the label area. The use of a porous material to construct the sample receiving area and the labeling area results in some sample solution and detection particles being retained in the porous material. Although a labeled zone comprising a porous material having a reversibly immobilized portion necessary for detection can be used in embodiments of the present invention, the embodiments of the present invention are preferably a sample of a lateral flow strip. Utilizes a detection particle or portion that is kept in a different area of the device than the containment area and comprises a non-porous material with low fluid retention characteristics. This approach allows the nucleic acid target-containing sample to be labeled before being introduced into the porous component at the sample receiving end of the lateral flow component of the device, thereby allowing sample material and detection particles in the porous labeling zone. It is not necessary to maintain and / or disappear. This method allows various treatments of samples in the presence of detection moieties, such as double-stranded targets or single-stranded targets, without concern for temperature effects on porous sample containing or labeled area materials or lateral flow detection strip materials. Further treatment with high temperatures is possible to achieve the modification of the secondary structure. In addition, although there is no lateral flow contact with the sample receiving area, the use of a fluid component, such as a label area that is controlled by a vent or valve, remains in contact for a period of time during which the target and target are controlled by the fluid flow control system It becomes. Thus, embodiments of the present invention may differ from conventional lateral flow test strips where the sample and detection particle interaction times and conditions are determined by the capillary transport properties of the material. By incorporating the detection particles into the temperature control chamber, the double-stranded nucleic acid can be denatured, and efficient hybridization-based detection becomes possible. In an alternative embodiment, fluorescence is used to detect nucleic acid amplification using a combination of LEDs, photodiodes and optical filters. These optical detection systems can be used for real-time nucleic acid detection and quantification during amplification and post-amplification endpoint detection.

  Embodiments of the present invention include low cost point-of-use systems in which nucleic acid samples are selectively amplified and detected. A further embodiment is a high-simply lateral flow-based nucleic acid sample preparation and passive fluid flow control (Title 13 of International Publication No. 70 / 9th International Publication No. 13 / Aug. 70 / Aug. No. 13 / Ann. Including integration with a nucleic acid sample preparation device, as described in the issue brochure. One embodiment of the device preferably includes both a plastic fluid component and a printed circuit assembly (PCA), optionally housed in a housing that protects the active component. Temperature regulation, fluid and reagent mixing are preferably regulated by a microcontroller. The reaction cassette is preferably actuated vertically, so that hydrostatic pressure, capillary forces and surface tension control fluid movement within the device in conjunction with a vent actuated by a microcontroller.

  Referring to the exemplary schematic diagram of FIG. 1, a nucleic acid sample has been added to the sample chamber 10. Nucleic acid samples can be added online (ie, an integrated nucleic acid preparation subsystem), a separate nucleic acid preparation step (one of many commercially available methods, such as a spin column), followed by pipetting of purified nucleic acid into the device or unprocessed It may be obtained from a nucleic acid containing sample. Preferably, a reagent mix, which may be in liquid or dry form, containing all components necessary for the amplification reaction, such as buffers, salts, dNTPs, rNTPs, oligonucleotide primers and / or enzymes, is already present in the sample chamber. Present or added later instead. In some embodiments, the reagent mix is lyophilized to form lyophilized reagent 20. When the sample is introduced into the sample chamber, the reagent and sample mix so that the reagent acts on the sample. An optional bubble mixing step may be optionally performed to further mix the sample with the reagent or to resuspend the reagent. The fluid is then preferably directed through the inlet channel 40 to one or more amplification chambers 30 below the sample chamber when the device is in a vertical orientation. An outlet channel 45 connects the amplification chamber 30 to the next chamber. Multiplexed amplification can be achieved by placing multiple primer sets in the amplification chamber to facilitate multiplex testing in which multiple amplicons are produced. In addition, circuit boards and fluid designs in which multiple amplification and detection chambers are incorporated into the device accommodate multiple parallel amplification reactions that can be singleplex or multiplex reactions. This approach reduces or eliminates the complexity known to those skilled in the art resulting from multiplexed amplification using multiple primer pairs in the same reaction. Moreover, by using multiple amplification reaction chambers, simultaneous amplification under different temperature regimes can meet the requirements for optimal amplification, such as different melting or annealing temperatures required for different target and / or primer sequences. Adaptable.

  Fluid movement from the first chamber to the second chamber of the device is preferably achieved by opening a vent connected to the second chamber, shown as FIGS. One embodiment of the vent includes two components, a vent pocket 50 in contact with a resistor mounted on a printed circuit board assembly (PCA) 75, one surface comprising a membrane, such as a polyolefin, and a vent. A vent channel 60 is provided to connect the pocket 50 to the microfluidic compartment under its control. When fluid is first added to the system in the sample chamber, the vent connected to the downstream chamber is sealed and the fluid does not pass through the channel connecting the two chambers. The microcontroller is responsible for delivering current to a heating element, for example a resistor 70 located at or near the membrane that forms one face of the vent pocket 50. The heat generated by the energized resistor breaks the thin membrane 80, thus opening the vent. Once opened, the vent causes fluid to fall from the first chamber to the second chamber by providing a path for air that is expelled upon entry of the fluid to exit the second chamber. Other embodiments of the vent pocket may include seals other than heat sensitive membranes and may utilize other methods of breaking the seal, such as puncture, tearing or dissolution.

  The amplification chamber is preferably in contact with a heater element to provide the means of temperature regulation necessary to support nucleic acid amplification. In some embodiments of the invention, the amplification chamber may contain oligonucleotides on at least a portion of the inner surface. As shown in FIGS. 1-3, one embodiment of the device includes an inlet channel 30 that leads from the sample chamber 10 to the amplification chamber 30 as described above, and preferably an outlet channel 45 and vent that leads from the amplification chamber 30 to the labeling chamber 90. A vent channel 60 leading to the pocket 50 is provided. It may be advantageous to place a thermally conductive material, such as thermal grease or compounds, at the interface between the amplification chamber wall 95 and the heater element 100. The microcontroller is preferably a simple on / off or proportional integral, preferably based on data collected from the temperature sensor 110, preferably by a metal oxide semiconductor field effect transistor (MOSFET), preferably to the resistive heating element. Adjust using a differential (PID) temperature control method or other algorithm temperature control known to those skilled in the art.

  Existing systems use active heating and cooling devices located in reusable equipment to provide temperature control for nucleic acid amplification performed on disposable cartridges, which can be replicated with removable disposable cartridges An instrument of sufficient accuracy that can reliably generate a thermal contract is inevitably required. This increases the cost and complexity of the instrument and reduces the reliability of the thermal interface between the instrument temperature control subsystem and the disposable cartridge fluid subsystem. Unlike these systems, embodiments of the present invention preferably comprise a temperature-controlling resistive heating element located in the disposable part of the device, such as the one shown above, for example in FIG. By placing the heating element and corresponding temperature sensor on the disposable component, a highly reproducible thermal coupling between the temperature control subsystem and the amplification and detection chambers they interface with can be produced. This approach provides a reliable means of coupling the fluid subsystem to the electronic thermal control subsystem that forms a thermally conductive interface during manufacturing. The excellent thermal contact that occurs between the electronic temperature control component and the fluid subsystem results in rapid temperature equilibration and thus rapid assay.

  Embodiments of the amplification chamber preferably include materials that can withstand repeated heating and cooling to temperatures in the range of approximately 30 ° C. to approximately 110 ° C. Even more preferably, the amplification chamber comprises a material that can withstand repeated heating and cooling to a temperature in the range of about 30 ° C. to about 110 ° C. at a rate of temperature change of about 10 ° C. to about 50 ° C. per second. The amplification chamber preferably maintains the solution therein at a temperature suitable for either the thermal cycling protocol (FIGS. 4A-4D) or the isothermal amplification protocol (FIG. 4E), depending on the programming of the microcontroller. it can. In some nucleic acid amplification applications, it is preferable to provide an initial incubation over a period of 1 second to 5 minutes at a high temperature, eg, a temperature between approximately 37 ° C. and approximately 110 ° C., to denature the target nucleic acid. . Subsequently, the reaction solution may be, but is not limited to, a temperature that causes nucleic acid double strand denaturation and a temperature suitable for primer annealing through hybridization to the target and extension of the primer through polymerase-catalyzed nucleic acid polymerization. Vary between at least two temperatures. The duration of incubation at each temperature required in the thermal cycling regimen may vary depending on the target nucleic acid sequence composition and the reaction mixture composition, but is preferably between about 0.1 seconds and about 20 seconds. Repeated heating and cooling is typically performed from about 20 to about 50 cycles. In embodiments that include isothermal amplification methods, the temperature of the reaction solution is maintained at a constant temperature for between about 3 minutes and 90 minutes, depending on the amplification technique used (in some cases at higher temperatures). After the initial incubation). When the amplification reaction is complete, the vent in communication with the labeling chamber is opened and the amplification reaction solution is transported to the labeling chamber located below the amplification chamber.

  In some embodiments, additional biochemical reactions may be performed in the amplification chamber before, during or after the amplification reaction. Such steps include, but are not limited to, reverse transcription, where RNA is transcribed into cDNA, multiplexing where multiple primer pairs simultaneously amplify multiple target nucleic acids, and amplification products are amplified. Real-time amplification detected during the reaction process. In the latter case, the amplification chamber may not contain a valve or outlet channel, and the amplification chamber is preferably equipped with an optical window or otherwise configured to query the amplicon concentration during the amplification reaction process. Has been. In one embodiment of real-time amplification, the fluorescence intensity of either a fluorescently labeled oligonucleotide complementary to the target nucleic acid or a fluorescent dye specific for double-stranded DNA is determined by the excitation light source, eg LED or diode laser and detection device, eg Monitored by a photodiode, as well as suitable optical components including, but not limited to, optical filters.

  In another embodiment of the invention, fluid movement is facilitated using resistive heating to expand the gas within the device chamber (FIG. 5). For example, heating the amplification chamber 30 causes the gas in the chamber to expand and escape as a bubble 120 from the vented channel, in this case the inlet channel 40. In some embodiments of the invention, such heating of the downstream chamber is used to generate sufficient bubbles to mix reagents present in the fluid volume of the upstream chamber, eg, the sample chamber 10. Good. When the heating element is shut off, the gas in the amplification chamber 30 cools and contracts, pulling the fluid 125 from the sample chamber 10 into the amplification chamber 30. By repeating the process several times, the entire fluid volume is directed from one chamber to another. In another embodiment of the present invention, such a mechanism may be used in conjunction with a resistor vent mechanism to eliminate fluid volume.

  The embodiment of the label chamber preferably provides a specific label of the amplified target nucleic acid produced in the amplification chamber and cooperates with the detection chamber to provide the test analysis results. As shown in FIG. 6A, the labeling chamber 90 is at least one of the inner surfaces in a carrier such as a polysaccharide, detergent, protein or other compound known to those skilled in the art to facilitate resuspension of the detection particles. Detection particles 130 that are partially dried, lyophilized or present may be included as a dry mixture of detection particles. The labeling chamber is preferably connected to an inlet channel 135 leading from the amplification chamber 30 as described above, an outlet channel 140 leading to the detection chamber, and a vent channel 150 leading to the vent pocket. Inlet channel 135 is typically the same channel as outlet channel 45 of amplification chamber 30. At the interface with the PCA, a thin layer of thermally conductive material, such as thermal grease, is preferably disposed between one face of the marking chamber and the resistive heating element.

  Suitable detection particles include, but are not limited to, fluorescent dyes specific to double-stranded nucleic acids, fluorescent modified oligonucleotides, or oligonucleotide conjugate stained microparticles or colloidal gold. Detection of amplicons includes “detection oligonucleotides” or other “detection probes” that are complementary to or otherwise capable of specifically binding to the amplicon being detected. Conjugation of detection oligonucleotides to microparticles may be performed by using streptavidin-coated particles and biotinylated oligonucleotides or by carbodiimide chemistry, which activates carboxylated particles in the presence of carbodiimide. And reacts specifically with the primary amine present on the detection oligonucleotide. Conjugation of the detection oligonucleotide to the detectable moiety may be performed internally or at the 5 'or 3' end. The detection oligonucleotide may be bound to the microparticles directly or more preferably through a spacer moiety, such as ethylene glycol or polynucleotide.

  In the case of a double-stranded DNA amplification product, detection is facilitated by heating the reaction solution after introduction into the detection chamber. When double-stranded DNA is dissolved and then cooled in the presence of the detection oligonucleotide, sequence-specific labeling of the amplified target nucleic acid occurs. To initiate double stranded DNA lysis, the fluid volume may be heated for approximately 1 to approximately 120 seconds using a resistive element under the labeling chamber. Once the solution has cooled to room temperature, the amplified target nucleic acid may be specifically hybridized to the detection microparticles. The reaction volume is then preferably directed to the area of the detection chamber below the labeling chamber by opening the detection chamber vent.

  In order to perform efficient labeling, the solubilized detection particles are preferably mixed well with the reaction solution. In an embodiment of the present invention, a second mixing method involving a resistance heater may be used to denature the double-stranded nucleic acid target during labeling and to sufficiently mix the detection microparticles in the reaction solution. Heating above the boiling point of the solution in the labeling chamber may be used to induce turbulence and mixing in the solution. The textured features of the chamber, such as the laser-etched line 132 (or series of such lines) shown in FIG. 6B, raises nucleated bubbles at the bottom and sides, preferably effectively stirring the solution. To do. This effect has proven to work at many heights regardless of the corresponding boiling point variation. Any solution rejected into the upper chamber by boiling preferably flows back into the labeling chamber during the next cooling. In some embodiments of the present invention, the inner surface region or marker chamber wall may be textured or otherwise processed to localize nucleate boiling to a particular chamber wall or surface. In other embodiments, one or more boiling stones may be placed in the labeling chamber to localize nucleate boiling at specific locations.

  Embodiments of the detection chamber of the present invention provide for specific detection of amplified target nucleic acids labeled in the labeling chamber. In certain embodiments of the invention, the detection is porous patterned with lines, dots or other visually distinguishable elements that contain binding moieties that can specifically or directly bind to a labeled amplicon. Realized by capillary up of a solution containing labeled amplicon through an absorbent strip of material (eg cellulose, nitrocellulose, polyethersulfone, polyvinylidene fluoride, nylon, charge-modified nylon or polytetrafluoroethylene) Is done. In some embodiments, the absorbent strip component of the device selects up to three porous substrates in physical contact: a surfactant pad containing amphiphilic reagents to improve uplift, a labeled amplicon Detection zone comprising a porous material (eg cellulose, nitrocellulose, polyethersulfone, polyvinylidene fluoride, nylon, charge-modified nylon or polytetrafluoroethylene) to which at least one binding site capable of binding is fixed And / or an absorbent pad to provide additional absorbent capacity. Unlike the lateral flow detection devices described above, the detection particles are preferably not contained within the lateral flow porous material in the detection chamber, but instead are retained upstream in the labeling chamber, Operations that substantially promote the formation of binding complexes between the amplicon and the detection particles, such as heating / boiling, may be performed prior to introduction of the resulting labeled nucleic acid into the porous component of the device.

  The “capture oligonucleotide” or “capture probe” is preferably immobilized on the detection strip element of the device by any of a wide variety of means known to those skilled in the art, eg UV irradiation. The capture probe captures the labeled nucleic acid as the solution containing the labeled nucleic acid pops up the capture zone, causing an increase in the concentration of the label at the capture probe site and thus the presence of the labeled target nucleic acid amplicon. Designed to produce a detectable signal indicative of A single detection strip can be patterned with one or more capture probes to enable multiplexed detection of multiple amplicons, determination of amplicon sequences, and assay quality control (positive and negative controls) Also good.

[Fluid subassembly layer]
The components of the fluid subassembly embodiment preferably include plastics, such as acrylic, polycarbonate, PETG, polystyrene, polyester, polypropylene, and / or other similar materials. These materials are readily available and can be manufactured by standard methods. As shown in FIGS. 3 and 7, the fluid subassembly includes both a chamber and a channel. The fluid chamber consists of a wall, two faces 160 and is connected to one or more channels, such as an inlet, outlet or vent. The channel can connect two fluid chambers and consists of a wall and two faces. The fluid chamber design preferably maximizes the surface area to volume ratio to facilitate heating and cooling. The internal volume of the chamber is preferably between about 1 μL and about 50 μL. The area of the chamber surface 160 in contact with the solution preferably matches the area that the heating element interfaces to make the fluid temperature uniform during heating. The shape of the fluid chamber may be selected to be compatible with the heating element and to provide a preferred form for solution entry or exit. In some embodiments, the chamber volume may be greater than the fluid volume to provide space for bubbles generated during device operation. The fluid chamber may have an extended extension that reaches the vent channel to prevent fluid from entering the channel by capillary action, or otherwise to block the vent mechanism. The portion of these chambers with which the vent channel is in communication optionally includes one or more non-wetting or hydrophobic surfaces that further reduce fluid ingress into the vent channel.

  In some embodiments, each fluid subassembly includes three laminated plastic sheets, one component 200 forming the fluid chamber wall, and two other surface components 210, 220 being Laminated to the first component to form a surface. The surface component 210 is optionally provided with a hole 212 for viewing the LED indicator 214. Surface component 220 preferably comprises lyophilized reagent 20, detection particles 130 and detection strip assembly 230, and preferably interfaces with PCB 75 via an adhesive shim 222 that may include a membrane with an adhesive border 224. In another embodiment, each fluid subassembly may include two plastic components, one component forming a wall and one face, and the other component being laminated to the first component. The chamber is sealed to form the second surface. In embodiments of the present invention, the plastic components of the fluid subassembly may be manufactured by means of industrial laser or water jet cutting, punching or stamping processes and injection molding.

  In some embodiments of the invention, the fluid chamber and channel wall thickness is in the range of approximately 0.025 mm to approximately 1 mm, preferably in the range of approximately 0.1 mm to approximately 0.5 mm. This thickness preferably satisfies both the requirements for the structural integrity of the fluid layer as well as the requirements to accommodate the sealing of the closed chamber under temperature and associated pressure. The thickness of the channel wall, in particular the vent channel wall, is preferably less than the chamber thickness and is in the range of approximately 0.025 mm to approximately 0.25 mm. The widths of the inlet and outlet channels are preferably selected to promote capillary action. The shallow vent channel provides improved stiffness to the fluid layer without adversely affecting venting to atmospheric pressure. The plastic forming surface of the fluid layer is preferably thinner than that forming the walls to maximize heat transfer. An optional thermal insulation layer 170 passes through several components of the fluid layer, surrounds the amplification and detection chamber, and contributes to thermal insulation of the temperature control chamber.

  The plastics used in the assembly of the fluid layer, such as acrylic and polyester, preferably comprise a hydrophobic material. In embodiments of the present invention, fluid layer components may be treated to improve wettability (ie, reduce hydrophobicity). Such processing ensures proper fluid control along with fluid channel dimensions. In some embodiments, a biocompatible surfactant, such as Triton X-100, may be applied to the uncoated material. The plasma discharge process is another optional process for modifying the hydrophobicity of the fluid contact surface.

  In some embodiments of the present invention, a double-sided adhesive film may be used to seal various components of the fluid layer. An adhesive film, such as one containing an adhesive shim 222 or membrane 224, is on the side of the internal component if the component is three fluid layers, or on one side if the component is two fluid layers. It is pasted. Before the surface component 220 is added to the other layer, further components of the fluid layer, such as detection strip assembly 230, detection particles 130 and lyophilized reagent 20, may be included. In some embodiments, the components may be laminated by applying pressure to improve adhesion. Adhesives that are known or known to adversely affect the performance of nucleic acid amplification reactions must be avoided. Acrylic or silicone adhesives have been successfully used in the present invention. One preferred adhesive film is SI7876 supplied by Advanced Adhesive Research. Other adhesives are used if they are found to be chemically compatible with the buffers, plastics and reaction chemistry used, while providing a robust seal against the temperatures exposed during device operation. It's okay.

  Referring to FIGS. 2 and 3, the vent pocket is preferably different in configuration from the other chambers. After the fluid layer configuration as described above, the vent pocket has an open surface on the side of the fluid layer that is compatible with the PCA layer 75. An additional plastic component comprising a thin non-heat resistant membrane 80 with one adhesive surface, preferably for application to the fluid layer adjacent to the PCA vent resistor 70 to form a vent pocket, Laminated to seal. Membrane 80 includes a polyolefin with a thickness between approximately 5 μm and approximately 200 μm, although other similar films may be used. This thin membrane is very suitable for sealing the vent pocket and at the same time facilitating drilling, so that when the current passes through the vent resistor and a rapid temperature rise occurs, Is done.

[Further components of the fluid layer]
As noted above, a plurality of additional components are preferably incorporated into the fluid layer of the present invention prior to final lamination and sealing. Prior to device assembly, reagents including buffers, salts, dNTPs, oligonucleotide primers and enzymes such as DNA polymerase and reverse transcriptase may be lyophilized or freeze-dried into pellets or cakes. Reagent lyophilization is well known in the art and includes dehydration by sublimation of an aliquot of frozen reagent under vacuum. Addition of certain formulations of lyoprotectants, such as sugars (disaccharides and polysaccharides) and polyalcohols to reagents prior to freezing may preserve enzyme activity and increase rehydration rate There is. Lyophilized reagent pellets or cakes are manufactured by standard methods and, once produced, are reasonably durable and can be easily placed in a specific chamber of the fluid layer prior to laminating the final surface. it can.

  In some embodiments of the invention, the detection particulate is another additional component of the fluid layer. In some embodiments, these microparticles may be lyophilized as described for the reaction reagents above. In other embodiments, the particulates in the liquid buffer may be applied and dried directly on the inner surface of the fluid chamber prior to sealing. The liquid buffer containing the microparticles preferably also includes sugar and polyalcohol that aid lyophilization. Direct incorporation of the microparticles in the aqueous buffer prior to drying into the fluid layer can simplify and reduce the final manufacturing cost, ensure that the microparticles are thoroughly mixed with the reaction solution, and are incorporated into the detection particles. Heating or nucleate boiling as described above may be required for both denaturing double stranded nucleic acid products for hybridization.

  In some embodiments of the present invention, a lateral flow detection strip assembly is also incorporated into the fluid layer. The detection strip preferably comprises a membrane assembly consisting of at least one porous component and may optionally comprise an absorbent pad, a detection membrane, a surfactant pad and a backing membrane. The detection membrane is made of nitrocellulose, cellulose, polyethersulfone, polyvinylidene fluoride, nylon, charge-modified nylon or polytetrafluoroethylene and may be lined with a plastic membrane. As described above, the capture probe may be deposited and reversibly immobilized on the detection membrane in a linear, dot-like, or any pattern seen with the human eye. The deposited oligonucleotide may be permanently immobilized by UV irradiation of the detection membrane after deposition of the capture probe. The surfactant pad may comprise a porous substrate, preferably having minimal nucleic acid binding and fluid retention properties, allowing unimpeded migration of nucleic acid product and detection microparticles. The surfactant pad may comprise a material such as glass fiber, cellulose or polyester. In an embodiment of the present invention, a formulation comprising at least one amphiphilic reagent is dried on a surfactant pad in order to transfer the sample uniformly through the detection membrane. The absorbent pad may contain any absorbent material, making it easier to induce sample lift through the detection membrane assembly. Using an adhesive backing membrane, such as a double-sided adhesive membrane, as a base, the detection membrane component first places the detection membrane, followed by any absorbent pad and / or surfactant pad from approximately 1 mm with the detection membrane. Construct by placing in physical contact with overlap between approximately 2 mm.

[Electronic subassembly layer]
In some embodiments, the printed circuit board (PCB) includes a standard 0.062 inch thick FR4 copper clad laminate material, but standard substrate materials and thicknesses may be used. Electronic components such as resistors, thermistors, LEDs and microcontrollers preferably comprise off-the-shelf surface mount devices (SMDs) and are arranged according to industry standard methods.

  In another embodiment, the PCA can be integrated with the cassette wall and comprises a flexible plastic circuit. Flexible circuit materials such as PET and polyimide may be used. The use of flexible plastic circuits is well known in the art. In another embodiment, the heating element and temperature sensor are mounted on a plastic fluid layer by Soligie, Inc. Screen printing may be performed using technology developed by companies such as.

  In some embodiments of the invention, the PCB thickness and the amount and placement of copper in the area surrounding the resistance heater are adjusted for temperature control of the reaction solution in the fluid layer. This can be achieved using the standard manufacturing techniques already mentioned.

  Examples of resistor heater assemblies are shown in FIGS. In some embodiments of the present invention, the resistor is a thick film 2512 package, but other resistors may be used. The heating chamber in the fluid layer is preferentially sized similar to the size of the resistor so that the entire chamber is heated uniformly. A single resistor of this size is sufficient to heat approximately 15 μL of solution, assuming a fluid layer thickness of 0.5 mm. The schematic of FIG. 3 shows two resistors 100 forming a heater sufficient to heat approximately 30 μL of solution, assuming a fluid layer thickness of 0.5 mm. In this case, the resistors are preferably each 40 ohms and arranged in a parallel arrangement.

  In some embodiments of the present invention, the temperature sensor 110 comprises a thermistor, such as a 0402 NTC device, preferably having a height similar to that of the 2512 resistor package. The thermistor is preferably aligned adjacent to or between the resistor heaters in the case of a single resistor or two resistor configuration, respectively. Either one. For example, see FIG. The close alignment of these electronic elements only creates a very narrow air gap between them. Furthermore, applying thermal compound before assembling the fluid layer with the electronic layer provides good thermal contact between the fluid layer, the resistor and the thermistor.

  In some embodiments of the invention, the vent resistor 70 is a thick film 0805 package, but similar resistors may be used.

  In some embodiments of the invention, the microcontroller is an AVR Atmega32. The microcontroller is preferably adapted to the complexity of the fluid system. For example, with multiplexing, the number of individual vents and heaters corresponds to the number of microcontroller I / O lines. The memory size can be chosen to accommodate the program size.

  In one embodiment of the invention, an N-channel MOSFET in an SOT-23 package operating in an ON-OFF mode is used to modulate the current load on the vent and heater resistor. The modulation signal is transmitted through the microcontroller. In another embodiment, pulse width modulation schemes and / or other control algorithms can be used for higher temperature management of the fluid. This is typically handled by a microcontroller and may require additional hardware and / or software features known to those skilled in the art.

[Assembly of the final device]
Final assembly of the fluid, electronic and housing components into the finished device is preferably done to improve the thermal contact between the PCA heating element and the chambers and / or pockets present in the fluid layer and Start by laminating the electronic layer 75. As shown in FIG. 9, the adhesive shim 222 joins both two layers together so that a horizontal contact is made between the flat fluid layer and the locally raised electronic components present on the PCA. To. To further improve the thermal contact, a thermal compound or grease may be placed on the heating element prior to lamination. After assembly of the fluid and electronic layers, a protective plastic housing may be applied to obtain the final device.

  Depending on the application, different embodiments of the invention may be most useful. Some embodiments comprise a device that operates a smaller disposable unit in which the small control base unit contains a nucleic acid amplification and detection system. This particular embodiment helps to reduce the cost of individual diagnostic tests. A representative device designed for this purpose is shown in FIG. As noted above, the electronic functions of such devices are preferably divided into two separate subassemblies. The disposable subassembly 260 includes pin connectors 270 or other similar electronic connectors as well as low cost electronic components, including components that interact directly with fluid system components, such as amplification chamber heating element 100, sign chamber heating element 265. A vent heating element 70, a temperature sensor such as a thermistor and optional LED indicator 214. Connector 270 preferably provides current to the resistive heater along with power and signal lines to the thermistor. The reusable subassembly or base unit 280 preferably includes reusable components such as a microcontroller, MOSFET, switch, power or power jack 275 and / or battery, optional cooling fan, optional user interface. And a connector 272 that is compatible with the connector 270 of the disposable subassembly 260. When the subassemblies are coupled via connectors 270 and 272, the base unit 280 preferably supports the disposable subassembly 260 in a substantially vertical or near-vertical orientation. Although a substantially vertical orientation is preferred in some of the embodiments described herein, the device may be tilted to operate, particularly when certain pathways are coated to reduce the wetting angle of the solution used. Similar results may be obtained.

  Another embodiment includes a device in which the entire assembly is disposable, as shown in FIG. In this embodiment, there is only a single electronic assembly powered by a 9 volt battery 305, preferably coupled to the back side of the device via terminal 307, as shown in FIG. 11C. A microcontroller 300, power conditioning circuit 302 and MOSFET 310 are also preferably located on the back side of the device, as shown in FIG. 11B, but in contact with the fluid layer, the opposite side shown in FIG. It comprises an element 100, a sign chamber heating element 265, a vent heating element 70 and a temperature sensor. The device shown in FIG. 11 is designed to incorporate chambers and other components that are required to perform two reactions, amplification and labeling reactions, in parallel for multiplexing applications. This particular embodiment is ideal for applications where testing is performed remotely. The device may also be powered from a power adapter or another battery or batteries of sufficient capacity.

  In order to provide a sample-to-result molecular test, any of the above embodiments of the present invention provides a sample that provides nucleic acid as output to the sample chamber 10 via channel 325. It may interface 320 to the preparation system. This is the 13th International Publication No. 70 / A9, titled “Highly Simplified Lateral Flow-Based Nucleic Acid Sample Preparation and Passive Fluid Flow Control” 9 / A 59/9. It is shown using a sample preparation technique as described in the brochure. An embodiment of the resulting integrated device is shown in FIG.

[Fluid sub-assembly with multiple wall components]
In some embodiments, as shown in FIG. 7, the fluid subassembly may comprise three laminated plastic sheets, one sheet forming the wall of the fluid chamber and the other two components being The surface is laminated on the first sheet. In another embodiment, the fluid subassembly may include two plastic components, one component forming a wall and one face, and the other component being laminated to the first component. The chamber is sealed to form the second surface. In embodiments of the present invention, the plastic components of the fluid subassembly may be manufactured by means of industrial laser or water jet cutting, punching or stamping processes and injection molding. In another alternative embodiment, the fluid subassembly comprises a layer stacked such that the detection chamber is located in a separate layer of the device and the detection chamber is disposed in front of the layer comprising the amplification chamber and the label chamber. You may be prepared. This physical arrangement reduces the width of the device while also providing additional functionality. In particular, according to this embodiment, the detection strip is positioned in the detection chamber over and over the label chamber, and the heater element under the label chamber used (during the detection step of the assay) is in the detection chamber. Allow temperature to be controlled. Control of the detection chamber temperature allows high temperatures to be used during detection strip hybridization. By using temperature-mediated control of the stringency of hybridization during hybridization-based detection, hybridization specificity can be improved, for example, by closely related nucleic acid sequences (eg, single nucleotide polymorphisms). Useful in identifying types).

  FIG. 13 illustrates the components of a multilayer fluid cassette assembly 290 of an embodiment of the present invention, as described immediately above. The first wall component 300 comprises a detection chamber 302 for receiving a detection strip 305 and a part 304 of the sample chamber. The second wall component 310 comprises another portion 306 of the sample chamber, an amplification chamber 314, a labeling chamber 316, a vent pocket 318 and a corresponding channel. The three surface components 330, 335, 340 form a chamber, pocket and channel. The surface component 335 acts as the back surface of the wall component 300 and the front surface of the wall component 310 to provide a solution containing the labeled target nucleic acid that moves from the label chamber 316 to the detection chamber 302 and the opening 303 to form the sample chamber. An opening 345 is provided. The component layers are preferably bonded together by a silicone transfer adhesive. The internal surface is preferably treated to control wetting. A reagent, a lateral flow assembly including the detection strip 305 and a thermofusible thermoplastic vent valve 320 are preferably added during manufacture. The adhesive membrane is preferably sealed over the vent pocket.

  FIG. 14 shows an exploded view of a disposable assay cartridge 350 incorporating the fluid layer 290 of FIG. The assay cartridge 350 includes a front shell microfluidic cassette assembly 290, a bonding tape 360, a circuit board 370 and a rear shell 380. FIG. 15 is a diagram of a disposable PCA / fluid assembly 350 located at the docking station 400. Sample is added to the sample chamber via sample port 390. The docking station preferably contains control electronics and a power source and may include buttons for initiating the electronic steps required for the assay.

[Example 1: Method of amplification and detection of target nucleic acid for diagnosis of Candida riviberactor infection in citrus]
Citrus leaf tissue was tested for the presence of the citrus greening virulence factor Candida riviberacta Asiaticus using an embodiment of the present invention in which the disposable component interfaces with a reusable dock.

  A partially disposable device as described above was prepared. The reusable unit consisted of a standard 1.5 ounce copper clad PCB. The circuit components included an ATmega 328 microcontroller, a 0.5 amp N-channel MOSFET, an SMD resistor, and a power conditioning component. The plastic shell formed by stereolithography (SLA) covered the substrate and the tactile switch. A Mespin connector was attached to the top surface to allow vertical connection to the disposable PCA. The disposable PCA consisted of a similar PCB with a thick film resistor, 0402 thermistor and 0603 LED. A right angle male pin connector was placed at one end of the board so that it was oriented vertically when the reusable unit was inserted into the female socket.

  The fluid layer was composed of two surface components, a wall component and a thin membrane. The surface component was made of 0.004 inch polyester (PET). Wall components are available from Advanced Adhesives, Inc. Made from 0.5 mm acrylic laminated with a 0.002 inch silicone transfer film from The vent membrane is made of 0.0005 inch polyolefin and 3M Inc. Made from a 0.004 inch solvent resistant acrylic adhesive. Individual components are described in Universal Laser Systems, Inc. And cut using a VersaLaser 3.5 laser cutter. Prior to assembly, all laser-cut plastic fluid components except the membrane component were placed in a sonication bath containing 100 mM sodium hydroxide and 0.1% sodium dodecyl sulfate and sonicated for 30 minutes. Any debris, contaminating nucleic acid or nuclease was removed. The cleaned plastic component was finally washed with nuclease-free water. Wall and surface components (toward the PCA) were first laminated by applying a pressure of 34.5 MPa (5000 psi). Detection oligonucleotide conjugate polystyrene beads in 500 mM sucrose were deposited in a labeling chamber and dried under vacuum. After drying, a double-sided tape strip was placed in the detection chamber and the detection membrane component was assembled using a nitrocellulose membrane strip, an Accuflow-P surfactant pad and a blotting paper acting as an absorbent pad. . In some cases, lyophilized beads composed of reactive enzymes and excipients were added to the sample chamber. Finally, the fluid layer was sealed with other surface components and the vent membrane components were stacked to seal the vent pocket. Silicone thermal compound (Radio Shack, Inc.) was thinly applied to the amplification and labeling resistors and the fluid and electronic layers were laminated using an adhesive shim.

After completion of device assembly, 28 μL of reaction mixture was added to the sample chamber. Depending on the experiment, the enzyme required for amplification is added to the reaction mixture in liquid form (FIG. 16A) or is present in the form of a lyophilized cake incorporated in the fluid chamber sample chamber (FIG. 16B). ) Either. In both cases, the nucleic acid template used was extracted from infected plant tissue using QIAshredder and spin column kit (Qiagen, Inc.). The primers hyvl_For and hyvl_Rev were used to amplify a 139 bp nucleic acid sequence for diagnosing the presence of the phytopathogenic bacterium Candida reversibacter asiaticus. A pre-prepared amplification buffer (10X) containing 400 mM Tris-HCl (pH 8.4), 10 mM ammonium sulfate, 100 mM potassium chloride and 0.25% Triton X-100 produces a unique amplification reaction chemistry I let you. The following was contained in 20 μL of each reaction solution.
9.4 μL water 2.0 μL 10 × amplification buffer 2.0 μL DMSO
0.4μL potassium chloride (2M)
0.5μL Magnesium chloride (100mM)
0.5 μL dithiothreitol (100 mM)
0.5 μL dNTP (10 mM)
2.0 μL Primer sets hyvl_For and hyv_Rev (8 μΜ each)
0.5 μL VentR (exo) DNA polymerase (2 U / μL) ^*
0.2 μL EtSSB, Extreme thermostable single chain binding protein (500 μg / mL) ^*
2.0 μL healthy or C.I. DNA (17.2 ng / μL) extracted from tissues infected with Riberibacter
^{* If} dissolved or contained lyophilized enzyme, replaced with water.

  The amplification chamber vent and the start of the amplification and detection program were done by pressing a tactile switch that served as the start button of the reusable unit. After venting, the reaction solution entered the amplification chamber where the solution was heated to 85 ° C. for 2 minutes, followed by 40 cycles of 76 ° C. for 10 seconds and 60 ° C. for 25 seconds. After the thermal cycle was completed, the reactants were flowed into the labeling chamber by initiating venting with a microcontroller. The labeling chamber contained dried blue stained polystyrene detection microspheres on one inner surface of the labeling chamber in the presence of 500 mM sucrose. The detection oligonucleotide conjugated to the stained microspheres was complementary to the sense strand of the nucleic acid amplification product. The labeling chamber was heated to 105 ° C. for 2 minutes and then maintained at 90 ° C. for 30 seconds to induce boiling and thorough mixing of the polystyrene beads and denaturation of the double stranded DNA product. After heating, the reaction solution in the labeling chamber was allowed to cool for 2 minutes. The detection chamber was vented to allow solution to flow from the label chamber to the detection chamber and onto the detection strip assembly. Three capture lines were immobilized on the lateral flow membrane. These were, from the bottom of the device, a negative control oligonucleotide that was not complementary to any assay target, a capture probe that was complementary to the amplification product, and a positive control oligonucleotide that was complementary to the detection probe. As clearly shown in FIG. 16, the present invention successfully amplified and detected the target nucleic acid without detecting cross-hybridization to the negative control line.

The sequence of the amplification primer used was as follows.
hyvl_For
ggccgtttta acacaaaaaga tgaatatcat agataggggta gtcaa (SEQ ID NO: 1)
hyvl_Rev
cggccatttt agataaatca atttgtttta gtttagatac atcaatttttt (SEQ ID NO: 2)
The sequence of capture and detection oligonucleotides used was as follows:
Capture tcgtttgagt aggtagagacc nnnnnnnnnnnn nt (SEQ ID NO: 3)
Detection / 5AmMC12 / aattgagga tgacgtgata gttacgacc aacatctt / 3Phos / (SEQ ID NO: 4)

  A more complete description of the amplification process can be found in U.S. Provisional Patent Application No. US Pat. Appln. No. 5,056,086, entitled “Oscillating Amplification Reaction for Nucleic Acids,” incorporated herein by reference. 61 / 477,437. This process allows the use of larger solution volumes with higher sensitivity and does not require active cooling to perform thermal cycling. Since the process requires only passive cooling, a narrow cycling temperature range and is not substantially affected by temperature tolerances that are less stringent than those typically used in PCR, a simple resistance heating element may be used. Therefore, the device is miniaturized and inexpensive. Moreover, the amplification chamber is preferably flat on the side adjacent to the heating resistor, so that good thermal contact is provided, so that excellent thermal coupling is feasible. This thermal interface may be improved by using a thermally conductive adhesive compound.

Example 2: Methods for isolation, amplification and detection of target nucleic acids for diagnosis of Candida riviberactor infection in citrus
A partially disposable device as described above was prepared. The reusable unit consisted of a standard 1.5 ounce copper clad PCB. The circuit components included an ATmega 328 microcontroller, a 0.5 amp N-channel MOSFET, an SMD resistor, and a power conditioning component. A plastic shell formed by stereolithography (SLA) covers the substrate and the tactile switch. A Mespin connector was attached to the top surface to allow vertical connection to the disposable PCA. The disposable PCA consisted of a similar PCB with a thick film resistor, 0402 thermistor and 0603 LED. A right angle male pin connector was placed at one end of the substrate to give a vertical orientation when the reusable unit was inserted into the female socket.

  The fluid layer was composed of two surface components, a wall component and a thin membrane. The surface component was composed of 0.004 inch polyester. Wall components are available from Advanced Adhesives, Inc. Composed of 0.5 mm acrylic laminated with a 0.002 inch silicone transfer membrane from Walls and surface components are created to accommodate the fluid layer integrated with the sample preparation subsystem, and the purified nucleic acid is deposited during the elution phase of the sample preparation process during lamination to the sample preparation subsystem. An opening and channel are provided that are positioned to be transmitted into the sample chamber of the present invention. The vent membrane is made of 0.0005 inch polyolefin and 3M Inc. Made from a 0.004 inch solvent resistant acrylic adhesive. Individual components are described in Universal Laser Systems, Inc. And cut using a VersaLaser 3.5 laser cutter. Prior to assembly, all laser-cut plastic fluid components except the membrane component were placed in a sonication bath containing 100 mM sodium hydroxide and 0.1% sodium dodecyl sulfate and sonicated for 30 minutes. Any debris, contaminating nucleic acid or nuclease was removed. The cleaned plastic component was finally washed with nuclease-free water. Wall and surface components (toward the PCA) were first laminated by applying a pressure of 34.5 MPa (5000 psi). Detection oligonucleotide conjugate polystyrene beads in 500 mM sucrose were deposited in a labeling chamber and dried under vacuum. After drying, a double-sided tape strip was placed in the detection chamber and the detection membrane component was assembled using a nitrocellulose membrane strip, an Accuflow-P surfactant pad and a blotting paper acting as an absorbent pad. . In some cases, lyophilized beads composed of reactive enzymes and excipients were added to the sample chamber. Finally, the fluid layer was sealed with other surface components and the vent membrane components were stacked to seal the vent pocket. Silicone thermal compound (Radio Shack, Inc.) was thinly applied to the amplification and labeling resistors and the fluid and electronic layers were laminated using an adhesive shim.

  The sample preparation subsystem with which the fluid layer of the present invention is interfaced was made from a laser cut acrylic layered to form a physical support for the buffer reservoir and the absorbent material components of the subsystem. The passive buffer exchange structure is described in "Highly Simplified Lateral Flow-Based Nucleic Acid Sample Preparation 70th Publication No. 9 / Publication of Passive Fluid International Control, No. 70," published in International Publication No. 70/59. It was cut in the form described in the (A1) pamphlet. Nonwoven nylon was used as the buffer exchanger material. Whatman GF / B glass fiber filters were used as the nucleic acid affinity matrix. Cotton gauze was used as an absorbent pad to provide a suitable volume of absorbent sink.

  Four 1.5 mm biopsy punches collected from plant tissue, especially the central citrus leaf vein near the petiole, were briefly ground in a microcentrifuge tube in 150 μL extraction buffer (4 M guanidine thiocyanate, 25 mM Tris, pH 6.4). did. 200 μL wash buffer 1 (2M guanidine thiocyanate, 30% ethanol, 25 mM Tris, pH 7.4) and 800 μL wash buffer 2 (400 mM NaCl, 50% ethanol, 50 mM Tris, pH 6.4) are added to each reservoir Immediately after, the resulting crude extract was introduced into the sample reservoir of the sample preparation subsystem. Fifteen minutes after sample addition, the nucleic acid binding matrix of the sample preparation component was “punched out” into the elution chamber below and the nucleic acid was eluted with 50 μL of reaction buffer. Punching and reaction buffer injections were performed by pushing a 1 cc tuberculin syringe (no needle) through the underlying affinity matrix and removing the matrix into the underlying elution chamber. The elution chamber was connected to the sample chamber of the present invention by a specially designed channel in the fluid layer. When the plunger of the syringe is depressed, the captured nucleic acid elutes and flows through the channel into the sample chamber.

Elution buffer, with the exception of enzymes, target amplification by a unique amplification technique, including primers hyvl_For and hyvl_Rev, which selectively amplify a 139 bp nucleic acid sequence for diagnosing the presence of the phytopathogenic bacterium Candida ribus rebylacta asiaticus All necessary reagents were included. Amplification buffer (10X) was prepared in advance and contained 400 mM Tris-HCl (pH 8.4), 10 mM ammonium sulfate, 100 mM potassium chloride and 0.25% Triton X-100. 20 μL of elution buffer contained:
12.1 μL water 2.0 μL 10 × amplification buffer 2.0 μL DMSO
0.4μL potassium chloride (2M)
0.5μL Magnesium chloride (100mM)
0.5 μL dithiothreitol (100 mM)
0.5 μL dNTP (10 mM)
2.0 μL Primer sets hyvl_For and hyv_Rev (8 μΜ each)
Prior to energizing the device, the following enzymes are added to the eluted nucleic acid sample in the sample chamber and mixed briefly using a gel-added pipette tip.
1.0 μL Bent R (exo) DNA polymerase (2 U / μL)
0.4 μL Et SSB, Extreme thermostable single chain binding protein (500 μg / mL)
The amplification chamber vent and the start of the amplification and detection program were done by pressing a tactile switch that served as the start button of the reusable unit. After venting, the reaction solution entered the amplification chamber where the solution was heated to 85 ° C. for 2 minutes, followed by 40 cycles of 76 ° C. for 10 seconds and 60 ° C. for 25 seconds. After the thermal cycle was completed, the reactants were flowed into the labeling chamber by initiating venting with a microcontroller. The labeling chamber contained dried blue stained polystyrene detection microspheres on one inner surface of the labeling chamber in the presence of 500 mM sucrose. The detection oligonucleotide conjugated to the stained microspheres was complementary to the sense strand of the nucleic acid amplification product. The labeling chamber was heated to 105 ° C. for 2 minutes and then maintained at 90 ° C. for 30 seconds to induce boiling and thorough mixing of the polystyrene beads and denaturation of the double stranded DNA product. After heating, the reaction solution in the labeling chamber was allowed to cool for 2 minutes. The detection chamber was vented to allow solution to flow from the label chamber to the detection chamber and onto the detection strip assembly. Three capture lines were immobilized on the lateral flow membrane. These were, from the bottom of the device, a negative control oligonucleotide that was not complementary to any assay target, a capture probe that was complementary to the amplification product, and a positive control oligonucleotide that was complementary to the detection probe. As clearly shown in FIG. 14, the nucleic acid isolation, amplification and detection of the target nucleic acid was successful with the fully integrated device.

[Example 3: Method of amplification and detection of target nucleic acid for diagnosis of Candida riviberactor infection in citrus]
Crude citrus leaves for the presence of Candida greenfish pathogenic factor Candida reverbacter Asiaticus without prior nucleic acid isolation steps using an embodiment of the present invention in which disposable components interface with a reusable dock The tissue extract was tested.

  A partially disposable device as described above was prepared. The reusable unit consisted of a standard 1.5 ounce copper clad PCB. The circuit components included an ATmega 328 microcontroller, a 0.5 amp N-channel MOSFET, an SMD resistor, and a power conditioning component. The plastic shell formed by stereolithography (SLA) covered the substrate and the tactile switch. A Mespin connector was attached to the top surface to allow vertical connection to the disposable PCA. The disposable PCA consisted of a similar PCB with a thick film resistor, 0402 thermistor and 0603 LED. A right angle male pin connector was placed at one end of the board so that it was oriented vertically when the reusable unit was inserted into the female socket.

  The fluid layer was composed of two surface components, a wall component and a thin membrane. The surface component was made of 0.004 inch polyester. Wall components are available from Advanced Adhesives, Inc. Made from 0.5 mm acrylic laminated with a 0.002 inch silicone transfer film from The vent membrane is made of 0.0005 inch polyolefin and 3M, Inc. Made of 0.004 inch solvent resistant acrylic adhesive. Individual components are described in Universal Laser Systems, Inc. And cut using a VersaLaser 3.5 laser cutter. Prior to assembly, all laser-cut plastic fluid components except the membrane component were placed in a sonication bath containing 100 mM sodium hydroxide and 0.1% sodium dodecyl sulfate and sonicated for 30 minutes. Any debris, contaminating nucleic acid or nuclease was removed. The cleaned plastic component was finally washed with nuclease-free water. Wall and surface components (toward the PCA) were first laminated by applying a pressure of 34.5 MPa (5000 psi). Detection oligonucleotide conjugate polystyrene beads in 500 mM sucrose were deposited in a labeling chamber and dried under vacuum. After drying, a double-sided tape strip was placed in the detection chamber and the detection membrane component was assembled using a nitrocellulose membrane strip, an Accuflow-P surfactant pad and a blotting paper acting as an absorbent pad. . In some cases, lyophilized beads composed of reactive enzymes and excipients were added to the sample chamber. Finally, the fluid layer was sealed with other surface components and the vent membrane components were stacked to seal the vent pocket. Silicone thermal compound (Radio Shack, Inc.) was thinly applied to the amplification and labeling resistors and the fluid and electronic layers were laminated using an adhesive shim.

After completion of device assembly, 40 μL of reaction mixture was added to the sample chamber. Depending on the experiment, the enzyme required for amplification was either present in liquid form in the reaction mixture or in the form of a lyophilized cake incorporated in the fluid chamber sample chamber. In both cases, the assayed sample consisted of 4 μL of crude citrus tissue extract prepared by grinding 5 biopsy punches 1.5 mm in diameter in 500 μL of nuclease free water. The primers hyvl_For and hyvl_Rev were used to amplify a 139 bp nucleic acid sequence for diagnosing the presence of the phytopathogenic bacterium Candida reversibacter Asiaticus. A unique amplification reaction chemistry was generated. Amplification buffer (10X) was prepared in advance and contained 400 mM Tris-HCl (pH 8.4), 10 mM ammonium sulfate, 100 mM potassium chloride and 0.25% Triton X-100. Each of 40 μL of the reaction solution contained the following.
18.8 μL Water 4.0 μL 10 × Amplification Buffer 4.0 μL DMSO
0.8μL Potassium chloride (2M)
1.0 μL Magnesium chloride (100 mM)
1.0 μL dithiothreitol (100 mM)
1.0 μL dNTP (10 mM)
4.0 μL Primer sets hyv_For and hyv_Rev (each 8 μΜ)
1.0 μL Bent R (exo) DNA polymerase (2 U / μL) ^*
0.4 μL Et SSB, Extreme thermostable single chain binding protein (500 μg / mL) ^*
4.0 μL 5 biopsy punches (1.5 mm diameter obtained from the citrus petiole or the central vein close to the petiole of either healthy or C. reberibacter-infected citrus) in 500 μL water without nuclease or about 4 mm Citrus tissue extract produced by briefly grinding long petiole tissue
^{* If} dissolved or contained lyophilized enzyme, replaced with water.

  The amplification chamber vent and the start of the amplification and detection program were done by pressing a tactile switch that served as the start button of the reusable unit. After venting, the reaction solution entered the amplification chamber where the solution was heated to 85 ° C. for 2 minutes, followed by 40 cycles of 76 ° C. for 10 seconds and 60 ° C. for 25 seconds. After the thermal cycle was completed, the reactants were flowed into the labeling chamber by initiating venting with a microcontroller. The labeling chamber contained dried blue stained polystyrene detection microspheres on one inner surface of the labeling chamber in the presence of 500 mM sucrose. The detection oligonucleotide conjugated to the stained microspheres was complementary to the sense strand of the nucleic acid amplification product. The labeling chamber was heated to 105 ° C. for 2 minutes and then maintained at 90 ° C. for 30 seconds to induce boiling and thorough mixing of the polystyrene beads and denaturation of the double stranded DNA product. After heating, the reaction solution in the labeling chamber was allowed to cool for 2 minutes. The detection chamber was vented to allow solution to flow from the label chamber to the detection chamber and onto the detection strip assembly. Three capture lines were immobilized on the lateral flow membrane. These were, from the bottom of the device, a negative control oligonucleotide that was not complementary to any assay target, a capture probe that was complementary to the amplification product, and a positive control oligonucleotide that was complementary to the detection probe. The present invention successfully amplified and detected the target nucleic acid without detecting cross-hybridization of the detection strip to the negative control line.

[Example 4: Method of amplification and detection of target nucleic acid for detection of Candida reverbacter in citrus peafowl, Diaforina citri kuyama]
An embodiment of the present invention in which a disposable component interfaces with a reusable dock is made as described in Example 3 and without the prior nucleic acid isolation step, Candida greens revelactor, a virulence factor for citrus greening • Used to test crude insect whole extract prepared from Diaforina citri kuyama for the presence of Asiaticus.

In some cases, lyophilized beads composed of reactive enzymes and excipients were added to the sample chamber. After completion of device assembly, 40 μL of reaction mixture was added to the sample chamber. Depending on the experiment, the enzyme required for amplification was either present in liquid form in the reaction mixture or in the form of a lyophilized cake incorporated in the fluid chamber sample chamber. In both cases, the sample consisted of 4 μL of a solution prepared by grinding whole 5 Diaforina citri kuyama living in 500 μL of nuclease-free water. The primers hyvl_For and hyvl_Rev were used to amplify a 139 bp nucleic acid sequence for diagnosing the presence of the phytopathogenic bacterium Candida reversibacter asiaticus. A unique amplification reaction chemistry was generated. Amplification buffer (10X) was prepared in advance and contained 400 mM Tris-HCl (pH 8.4), 10 mM ammonium sulfate, 100 mM potassium chloride and 0.25% Triton X-100. Each of 40 μL of the reaction solution contained the following.

18.8 μL Water 4.0 μL 10 × Amplification Buffer 4.0 μL DMSO
0.8μL Potassium chloride (2M)
1.0 μL Magnesium chloride (100 mM)
1.0 μL dithiothreitol (100 mM)
1.0 μL dNTP (10 mM)
4.0 μL Primer sets hyv_For and hyv_Rev (each 8 μΜ)
1.0 μL Bent R (exo) DNA polymerase (2 U / μL) ^*
0.4 μL Et SSB, Extreme thermostable single chain binding protein (500 μg / mL) ^*
4.0 μL Extract of whole diaforina, citri, and quayama produced by briefly crushing five whole insects in 500 μL of nuclease-free water
^{* If} dissolved or contained lyophilized enzyme, replaced with water.

  The amplification chamber vent and the start of the amplification and detection program were done by pressing a tactile switch that served as the start button of the reusable unit. After venting, the reaction solution entered the amplification chamber where the solution was heated to 85 ° C. for 2 minutes, followed by 40 cycles of 76 ° C. for 10 seconds and 60 ° C. for 25 seconds. After the thermal cycle was completed, the reactants were flowed into the labeling chamber by initiating venting with a microcontroller. The labeling chamber contained dried blue stained polystyrene detection microspheres on one inner surface of the labeling chamber in the presence of 500 mM sucrose. The detection oligonucleotide conjugated to the stained microspheres was complementary to the sense strand of the nucleic acid amplification product. The labeling chamber was heated to 105 ° C. for 2 minutes and then maintained at 90 ° C. for 30 seconds to induce boiling and thorough mixing of the polystyrene beads and denaturation of the double stranded DNA product. After heating, the reaction solution in the labeling chamber was allowed to cool for 2 minutes. The detection chamber was vented to allow solution to flow from the label chamber to the detection chamber and onto the detection strip assembly. Three capture lines were immobilized on the lateral flow membrane. These were, from the bottom of the device, a negative control oligonucleotide that was not complementary to any assay target, a capture probe that was complementary to the amplification product, and a positive control oligonucleotide that was complementary to the detection probe. The present invention successfully amplified and detected the target nucleic acid without detecting cross-hybridization of the detection strip to the negative control line.

[Example 5: Amplification and detection method of target nucleic acid for detection of Candida reverbacter in Periwinkle (Cantarantus roseus)]
An embodiment of the present invention in which a disposable component interfaces with a reusable dock is made as described in Example 3 and without the prior nucleic acid isolation step, Candida greens revelactor, a virulence factor for citrus greening A crude extract of periwinkle (Cantarantus roseus) tissue was used to test for the presence of Asiaticus.

In some cases, lyophilized beads composed of reactive enzymes and excipients were added to the sample chamber. After completion of device assembly, 40 μL of reaction mixture was added to the sample chamber. Depending on the experiment, the enzyme required for amplification was either present in liquid form in the reaction mixture or in the form of a lyophilized cake incorporated in the fluid chamber sample chamber. In both cases, the sample consisted of 4 μL of a solution prepared by grinding 5 biopsy punches with a diameter of 1.5 mm in 500 μL of nuclease free water. Biopsy punches were obtained from either Candida vivibacter asiaticus infected or uninfected periwinkle (Cantarantus roseus). The primers hyvl_For and hyvl_Rev were used to amplify a 139 bp nucleic acid sequence for diagnosing the presence of the phytopathogenic bacterium Candida reversibacter asiaticus. A unique amplification reaction chemistry was generated. Amplification buffer (10X) was prepared in advance and contained 400 mM Tris-HCl (pH 8.4), 10 mM ammonium sulfate, 100 mM potassium chloride and 0.25% Triton X-100. Each of 40 μL of the reaction solution contained the following.
18.8 μL Water 4.0 μL 10 × Amplification Buffer 4.0 μL DMSO
0.8μL Potassium chloride (2M)
1.0 μL Magnesium chloride (100 mM)
1.0 μL dithiothreitol (100 mM)
1.0 μL dNTP (10 mM)
4.0 μL Primer sets hyv_For and hyv_Rev (each 8 μΜ)
1.0 μL Bent R (exo) DNA polymerase (2 U / μL) ^*
0.4 μL Et SSB, Extreme thermostable single chain binding protein (500 pg / mL) ^*
4.0 μL Periwinkle tissue extract produced by briefly crushing 5 biopsy punches 1.5 mm in diameter (collected from the petiole of periwinkle leaves) in 500 μL of nuclease-free water
^{* If} dissolved or contained lyophilized enzyme, replaced with water.

  The amplification chamber vent and the start of the amplification and detection program were done by pressing a tactile switch that served as the start button of the reusable unit. After venting, the reaction solution entered the amplification chamber where the solution was heated to 85 ° C. for 2 minutes, followed by 40 cycles of 76 ° C. for 10 seconds and 60 ° C. for 25 seconds. After the thermal cycle was completed, the reactants were flowed into the labeling chamber by initiating venting with a microcontroller. The labeling chamber contained dried blue stained polystyrene detection microspheres on one inner surface of the labeling chamber in the presence of 500 mM sucrose. The detection oligonucleotide conjugated to the stained microspheres was complementary to the sense strand of the nucleic acid amplification product. The labeling chamber was heated to 105 ° C. for 2 minutes and then maintained at 90 ° C. for 30 seconds to induce boiling and thorough mixing of the polystyrene beads and denaturation of the double stranded DNA product. After heating, the reaction solution in the labeling chamber was allowed to cool for 2 minutes. The detection chamber was vented to allow solution to flow from the label chamber to the detection chamber and onto the detection strip assembly. Three capture lines were immobilized on the lateral flow membrane. These were, from the bottom of the device, a negative control oligonucleotide that was not complementary to any assay target, a capture probe that was complementary to the amplification product, and a positive control oligonucleotide that was complementary to the detection probe. The present invention successfully amplified and detected the target nucleic acid without detecting cross-hybridization of the detection strip to the negative control line.

[Example 6: Amplification and detection method of target nucleic acid for detection of Candida riviberacta Asiaticus in Prunus quail (Cuscuta pentagonas)]
An embodiment of the present invention in which a disposable component interfaces with a reusable dock is made as described in Example 3 and without the prior nucleic acid isolation step, Candida greens revelactor, a virulence factor for citrus greening A crude extract of periwinkle (Cantarantus roseus) tissue was used to test for the presence of Asiaticus.

In some cases, lyophilized beads composed of reactive enzymes and excipients were added to the sample chamber. After completion of device assembly, 40 μL of reaction mixture was added to the sample chamber. Depending on the experiment, the enzyme required for amplification was either present in liquid form in the reaction mixture or in the form of a lyophilized cake incorporated in the fluid chamber sample chamber. In both cases, the sample consisted of 4 μL of a solution prepared by grinding a 1 cm long mosquito (Cuscuta pentagonus) vine in 500 μL of nuclease-free water. The primers hyvl_For and hyvl_Rev were used to amplify a 139 bp nucleic acid sequence for diagnosing the presence of the phytopathogenic bacterium Candida reversibacter asiaticus. A unique amplification reaction chemistry was generated. Amplification buffer (10X) was prepared in advance and contained 400 mM Tris-HCl (pH 8.4), 10 mM ammonium sulfate, 100 mM potassium chloride and 0.25% Triton X-100. Each of 40 μL of the reaction solution contained the following.
18.8 μL Water 4.0 μL 10 × Amplification Buffer 4.0 μL DMSO
0.8μL Potassium chloride (2M)
1.0 μL Magnesium chloride (100 mM)
1.0 μL dithiothreitol (100 mM)
1.0 μL dNTP (10 mM)
4.0 μL Primer sets hyv_For and hyv_Rev (each 8 μΜ)
1.0 μL Bent R (exo) DNA polymerase (2 U / μL) ^*
0.4 μL Et SSB, Extreme thermostable single chain binding protein (500 μg / mL) ^*
4.0 μL Cuscuta pentagona extract produced by briefly grinding a 1 cm long vine in 500 μL of nuclease free water.

  Although the invention has been described in detail with particular reference to the described embodiments, other embodiments can achieve the same results. Variations and modifications of the invention will be apparent to those skilled in the art and are intended to include all such modifications and equivalents. The complete disclosures of all patents and publications cited above are hereby incorporated by reference.

Claims (17)

A disposable platform for detecting a target nucleic acid,
A sample chamber for containing a sample containing the target nucleic acid;
An amplification chamber connected to the sample chamber via a first channel and connected to a first vent pocket via a second channel;
A labeling chamber connected to the amplification chamber via a third channel and connected to a second vent pocket via a fourth channel;
A detection subsystem coupled to the labeling chamber via a fifth channel and coupled to a third vent pocket via a sixth channel;
A plurality of resistance heating elements;
One or more temperature measuring devices, wherein the vent pockets are each sealed from the atmosphere by a non-heat resistant membrane located near one of the resistive heating elements.   The disposable platform of claim 1, further comprising a sample preparation stage comprising an outlet in fluid communication with an inlet of the sample chamber.   The disposable platform of claim 1, wherein a substantially planar dimension of the amplification chamber is substantially the same as a substantially planar dimension of a resistive heating element in thermal contact with the amplification chamber.   The disposable platform of claim 1, wherein the amplification chamber is not cooled by an active cooling device.   The disposable platform of claim 1, wherein the amplification chamber contains an amplification solution, the sample chamber comprises a liquid amplification reagent mix or a lyophilized amplification reagent mix, and / or the labeling chamber comprises detection particles.   The disposable platform of claim 1, wherein the labeling chamber is heatable using one of the resistive heating elements.   The disposable platform of claim 1, wherein the detection subsystem includes a lateral flow strip that does not include detection particles.   The chamber, the channel and the vent pocket are located on a fluid assembly layer, the electronic element is located on a separate layer including a printed circuit board, and the separate layer is coupled to the fluid assembly layer; The disposable platform according to claim 1.   The disposable platform of claim 1, wherein the detection subsystem is located on the fluid assembly layer or a second fluid assembly layer.   The disposable platform according to claim 1, wherein the volume of at least one of the chambers is between approximately 1 microliter and approximately 50 microliters.   The disposable platform of claim 1, further comprising a connector for coupling the disposable platform to a base unit that holds the disposable platform in a vertical or tilted orientation, rather than an external device. A method for detecting a target nucleic acid comprising:
Placing a sample containing the target nucleic acid in a sample chamber of a disposable platform;
Directing the disposable platform vertically or tilted;
Reacting the sample with a liquid or previously lyophilized amplification reagent mix;
Allowing the reacted sample to flow into the amplification chamber by opening the first vent pocket connected to the amplification chamber to the atmosphere;
Amplifying the target nucleic acid in an amplification chamber;
Allowing the amplified target nucleic acid to flow into the labeling chamber by opening a second vent pocket connected to the labeling chamber to the atmosphere;
Using the detection particles in a labeling chamber to label the amplified target nucleic acid;
Allowing a labeled target nucleic acid to flow into the detection subsystem by opening a third vent pocket connected to the detection subsystem to the atmosphere;
Detecting the amplified target nucleic acid.   The method of claim 12, wherein the amplifying step comprises amplifying the target nucleic acid using a resistive heating element located near the amplification chamber in a disposable platform.   The method of claim 12, further comprising passively cooling the amplification chamber.   13. The method of claim 12, further comprising heating the labeling chamber using a resistive heating element located near the labeling chamber in the disposable platform during the labeling step.   The method of claim 12, wherein the detection subsystem does not include detection particles.   13. The method of claim 12, further comprising controlling the operation of the disposable platform by using a docking station that is not an external device.